In Blender 2.8, how do I light an EEVEE scene with an HDR?
Yes and no.
EEVEE can't use mesh lights or HDRI lights &quot;properly&quot;. Why? Because EEVEE is not raytracer.
For further reading/watching please see:

Blender Cycles vs. Eevee 15 Limitations of Real Time Rendering in
Blender 2.8
Blender's Cycles vs. Eevee (Ray Tracing vs. Real
Time)
How does EEVEE work?
EEVEE and Cycles render lighting differences

What you can do about it.
Fake it. Or just try to do it.
You will not get the same results in EEVEE as in Cycles. Period. You can try to match HDRI lightning with use of Sun lamp, and smaller lamps (point, spot, area) to be as close as possible to source.
Render your image in Cycles and then by eyeballing try to reproduce as close as possible result in EEVEE.
EEVEE will use colors and light direction from HDRI but the rest like AO and shadows are not supported.
Example.

This is just a quick example of how you can try to mimic &quot;proper&quot; lightning and shadows. As you can see it's not nearly as good as Cycles result due to pretty complicated HDRI.
For second image I've used Sun lamp, two Area lights for blueish tint, EEVEE AO with high factor (3), Soft Shadows in EEVEE Shadows settings and a lot of tweaking under the light settings itself.
I'll not post settings screenshot on purpose as they will be always different for different scenes and there is no &quot;rule of thumb&quot; for them and posting mine could cause more distraction then learning value.